The overall objective of the Neuropathology Core is to prepare and interpret neuropathologic material derived from the various experiments described in Projects and Cores. Specific aims include: histologic processing of brain specimens for light and electron microscopy, an expert interpretation of neuropathologic alterations arising from cerebral hypoxia-ischemia or status epilepticus. Brains to be studied will include those of developing postnatal rats and rabbits previous subjected to cerebral hypoxia-ischemia or status epilepticus. Brains will be fixed in situ or by perfusion-fixation or immersion using a variety of fixatives. Thereafter, brains will be examined grossly and microscopically, and the extent of damage determined by specific scoring methods. Histologic processing will include those techniques required for paraffin or resin embedding followed by tissue sectioning. A variety of stains will be used to accentuate morphologic alterations. Histologic interpretation will be conducted by the Principal Investigator in collaboration with the Principal Investigators of the individual projects.